Free Run Mode - Analog Devices ADV7850 Hardware Manual

sdp_tbc_en, Addr 90 (SDP), Address 0x34[7]
This control is used to enable line TBC. When enabled, it only becomes active in VCR trick modes.
Function
sdp_tbc_en
1 
0
sdp_freeze_frame, Addr 94 (sdp_IO), Address 0x6F[1]
This control is used to continuously loop out a frame of video data from the TBC block. This feature will effectively allow the image to
be paused on screen. When this bit is set, new data will not be updated into the Frame memory. This bit is only valid when Frame TBC
is enabled.
Function
sdp_freeze_frame
0 <<
1
6.16

FREE RUN MODE

Free Run mode in the SDP Core is designed to provide a stable clock and predictable video when no signal is applied to an input or if a
signal cannot be decoded. The ADV7850 can automatically activate Free Run mode when
can be also forced by sdp_force_free_run
Free Run mode controls default color insertion and causes ADV7850 to generate a default clock. The state in which this happens can be
monitored via the sdp_free_run
The default color of Free Run mode can be set by the following registers:
• sdp_free_run_man_col_en
• sdp_free_run_y[7:0]
• sdp_free_run_u[3:0]
•
sdp_free_run_v[3:0]
ADV7850 can also output color bars instead of flat picture. To do this,
sdp_free_run_auto, Addr 90 (SDP), Address 0xDD[3]
This control is used to enable automatic free run operation. The part enters free run if no valid input video is detected.
Function
sdp_free_run_auto
1 
0
sdp_free_run_man_col_en, Addr 90 (SDP), Address 0xDD[2]
This control is used to enable the manual setting of video data output in video mode. If in free run, luma and chroma values are set by
sdp_free_run_y, sdp_free_run_v, and sdp_free_run_u.
Rev. A May 2012
Description
Enable line TBC (time base correction)
Disable line TBC (time base correction)
Description
Do not freeze Frame TBC input
Freeze Frame TBC input
regardless of the input
readback.
Description
Free run if no valid input video detected
Do not free run even if no valid input video detected
sdp_free_run_auto
state.
sdp_free_run_cbar_en
122
is set to 1. Free run mode
should be set to 1.
ADV7850